Calculus 2 : Finding Limits and One-Sided Limits

Study concepts, example questions & explanations for Calculus 2

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Example Questions

Example Question #111 : Finding Limits And One Sided Limits

Evaluate the limit:

Possible Answers:

Correct answer:

Explanation:

There is no limiting situation in this equation (like a denominator) so we can just plug in the value that x approaches into the limit and solve:

Example Question #112 : Finding Limits And One Sided Limits

Evaluate the limit:

Possible Answers:

Correct answer:

Explanation:

The limiting situation in this equation would be the denominator. Plug the value that x is approaching into the denominator to see if the denominator will equal 0. In this question, the denominator will not equal zero when x=4; so we proceed to insert the value of x into the entire equation.

Example Question #113 : Finding Limits And One Sided Limits

Screen shot 2015 07 28 at 12.15.15 pm

Given the above graph of , what is ?

Possible Answers:

Does Not Exist

Correct answer:

Does Not Exist

Explanation:

Examining the graph, we can observe that does not exist, as   is not continuous at . We can see this by checking the three conditions for which a function is continuous at a point :

 

  1. A value exists in the domain of

  2. The limit of exists as approaches

  3. The limit of at is equal to

 

Given , we can see that condition #1 is not satisfied because the graph has a vertical asymptote instead of only one value for and is therefore an infinite discontinuity at .

We can also see that condition #2 is not satisfied because approaches two different limits:   from the left and from the right.

Based on the above, condition #3 is also not satisfied because is not equal to the multiple values of .

Thus, does not exist.

Example Question #113 : Finding Limits And One Sided Limits

Evaluate the following limit:

Possible Answers:

Correct answer:

Explanation:

To evaluate the limit, we must determine whether it is right or left sided. The negative sign "exponent" on the 2 indicates that we are approaching from the left, or numbers slightly less than 2. So, we choose the part of the piecewise function that is for x values less than or equal to 2. Now, evaluating the limit, as natural log approaches zero, we get

Example Question #114 : Finding Limits And One Sided Limits

Evaluate the limit:

Possible Answers:

Correct answer:

Explanation:

To evaluate the limit, first we must pull out a factor consisting of the highest power term divided by itself (so we are pulling out a factor of 1):

After the factor we pulled out cancels to 1, and all of the negative exponent terms go to zero (as they approach infinity), what is left is our answer .

Example Question #115 : Finding Limits And One Sided Limits

Evaluate the limit:

Possible Answers:

Correct answer:

Explanation:

To evaluate the limit as x approaches infinity, we must first pull out a factor consisting of the highest power term divided by itself (so we are pulling out 1):

Once the term we pulled out becomes zero, we then look at the remaining terms. The denominator of the fraction goes to zero because the sum of the two terms with negative exponents is .

Thus, the entire limit goes to .

Example Question #114 : Finding Limits And One Sided Limits

Evaluate the limit:

Possible Answers:

Correct answer:

Explanation:

To evaluate the limit, we must first see whether it is right or left sided.

The negative sign "exponent" on the 1 indicates we are approaching one from the left side, or with numbers slightly less than 1.

Therefore, we must use the part of the piecewise function corresponding to numbers less than (or equal to) 1. When we evaluate the limit, we find that

 because the exponent of e is infinity. 

Example Question #161 : Limits

Evaluate the limit:

Possible Answers:

Correct answer:

Explanation:

When we evaluate the limit, we find that as  approaches , we approach . Because there is a negative sign in front of the function (we were given , the answer is still .

The fact that the limit is right sided doesn't change the outcome.

Example Question #115 : Finding Limits And One Sided Limits

Screen shot 2015 07 28 at 11.51.52 am

Given the above graph of , what is ?

Possible Answers:

Does Not Exist

Correct answer:

Explanation:

We first need to determine what the question is asking for. In this case because there is a plus sign in the exponent of zero we can interpret that as the limit of the function as x values approach zero from the right hand side. This means the values are going to be slightly larger than zero.

Examining the graph, we can observe that   as   approaches  from the right.

Example Question #162 : Calculus Ii

Screen shot 2015 07 28 at 11.58.54 am

Given the above graph of , what is ?

Possible Answers:

Does Not Exist

Correct answer:

Explanation:

First we want to check the three conditions for which a function  is continuous at a point :

  1. A value  exists in the domain of 

  2. The limit of  exists as  approaches 

  3. The limit of  at  is equal to 

Given , we can see that condition #1 is satisfied because the graph is approaching negative infinity at .

We can also see that condition #2 is satisfied because  approaches  from the right and from the left.

Based on the above, condition #3 is also satisfied because  is equal to .

Thus by examining the graph, we can observe that   as   approaches  from the left and from the right.

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